Cushioning device for a shuttle table



3 Shets-Sheet 1 m T 0. Hp j o o o o o 0 y a M 2" HF fipfiubfiyw 2y l I i I I l I I l l l l l I l I 1 l I l l l I l I I l\ f I n J 2 M- L %WMWILMHM|MWMMHIMMMWMMMMHHHMMPLQ ww NM. mh f R. J. LINDSEY CUSHIONING DEVICE FOR A SHUTTLE TABLE Jan. 26, 1960 Filed Nov. 15, 1957 Jan. 26, 1960 R. J. LINDSEY CUSHIONING DEVICE FOR A SHUTTLE TABLE Filed Nov. 15, 1957 3 Sheets-Sheet 2 m wwx INVENTOR.

Jan. 26, 1960 R. J. LINDSEY CUSHIONING DEVICE FOR A SHUTTLE TABLE 3 Sheets-Sheet 3 Filed Nov. 15, 1957 INVENTOR. Wzess Mi bzds- L BY #WJZ 5f WWW United States PatC CUSHIONING DEVICE FOR A SHUTTLE TABLE Robert J. Lindsey, Marion, Ohio, assignor to American Steel Foundries, Chicago, 11]., a corporation of New Jersey Application November 15, 1957, Serial No. 696,876

7 16 Claims. (Cl. 121- 38) The invention relates to hydraulic machinery and more particularly to a novel cushion device associated with a shuttle table usable on a hydraulic press and is a continuation-in-part of co-pending application, Serial No. 427,546, filed May 4, 1954, now abandoned.

In hydraulic presses and particularly that type of press employing a single acting ram, it is desirable to associate with said pressa shuttle table, whereby a plurality of dies or work areas may be carried on the table and progressively or alternately brought into position whereby work may be accomplished thereon by action of the press ram. Accordingly, the invention comprehends the incorporation with a press having a single acting ram of a novel shuttle table arrangement. More particularly the invention comprehends a novel cushioning device whereby the speed of the shuttle table as it approaches the extreme limits of its travel in either direction is controllable to avoid damage tothe shuttle table or press framework.

It is the primary object of the invention to provide a novel hydraulically actuated shuttle table arrangement for use on hydraulic presses.

It is a specific object of the invention to provide the shuttle table arrangement of the type described with a novel bleeding control whereby speed of the shuttle table is controllable as it approaches the extreme limits of travel in either direction.

These and other objects of theinvention will become apparent in the course of the following description and from the examination of. the concerned drawings, wherein:

Figure 1 is a top plan view fragmentarily illustrating a hydraulic press bed with a shuttle table mounted thereon;

Figure 2 is a sectional view taken along 22 of Figure 1;

Figure 3 is a fragmentary partially schematic drawing illustrating in detail the construction and operation of the shuttle table arrangement; and

Figure4 is a fragmentary sectional view of a modified form of the cushioning arrangement shown in Figure 3.

Directing attention to Figures 1 and 2, a press bed or frame is indicated generally at 2, said bed or frame comprising vertical guides 4 at opposite sides and extending longitudinally thereof. The guides 4 may be dowelled and bolted to the bed 2 as shown at 6.and 8 respectively. Abutments 10, 10 are positioned at opposite ends of the guides 4, said abutments being bolted in position by the cap screws-12. A sheet metal casing 14 is arranged to cover the guides 4 and abutments 10 whereby a generally improved appearance is given to the structure mounted on the bed of the press.

A shuttle table 16 is disposed on the bed 2 intermediate the guides 4 and abutments 10. Gibs 18, 18 are adjustably mounted on the internal sides of the longitudinal guides 4, said gibs 18 having machined angular surfaces at 20, 20 which complementally abut similarly machined ice angular surfaces formed at opposite edges of theshuttl 2 in a complementally machined slot on the underside of table 16. Additionally, the bed 2 is provided with a longitudinally extended machined strip 22 which is dowelled or otherwise securely held in such a position as to extend longitudinally of the bed 2. The strip 22 extends above the upper surface 24 of the bed 2 and is received the shuttle table 16, said slot being machined lengthwise of the shuttle table. The strip 22 and the guiding engagement of the gibs 20 with the table '16 serve to accurately guide movement of the table longitudinally of the bed 2.

therein. The end of each ram Directing attention to Figure 1 it will be seen that a pair of shuttling devices indicated generally at 30 are secured to opposite ends of the shuttle table 16.

Referring now to Figure 3, it will be seen that a pump '32 is arranged to draw hydraulic fluid from a reservoir 34. The pump 32 then directs the hydraulic fluid to a pressure intake port 36 on one side of a conventional; four-way operating valve used to control the system. The

valve 38 has connected thereto a line,40 whichreturns hydraulic fluid to the tank 34 from lines 46 or 48 The valve.

response to movement of the valve spool. additionally has ports 42 and 44 connected respectively to lines 46 and 48 which in turn are directed to the left, I

and right hand operating segments of the shuttling device.

It will be noted that the left and right hand operating.

segments 30 aretshown on the left and right hand side of the fragmentarily illustrated shuttle table 16 in Figure 3.-

It will be noted that the shuttle table 16 has a plurality of bores 50, 50 formed therein, said bores being preferably of cylindrical cross-section though other geometric patterns would reasonably satisfy the r'equirementsof the invention. Each bore 50 has a hollow ram 52.disposed the related abutment 10, as for example, by threadable engagement therewith at 54. A pipe tappedpassage 56 communicates with the hollow segment ofeach ram 52.

Conventional packing 58 and 60 is disposed in each bore 5010 surround the ram 52 and provide a fluid tight movable seal between the ram and the-table 16. A gland 62 serves to retain packing 58 and 60 in proper position and is rigidly secured to the table 16, as for example, by threadable engagement therewith as at 64. A spring plate .66 may be inserted in each bore 50 at the inboard end thereof, said spring plate offering a seat for one end of a spring 68 which in turn is compressed between the plate 66 and thefollower 70. The follower 70 is movably disposed in each bore 50. Each follower 70 has a plurality of longitudinal grooves 72 formed on the pcriphery thereof. The grooves 72 permit fluid to flow freely by the follower as will be more clearly ex-f The valve 38 is controllable either manually or automatically in response to the position of the shuttle table and may alternately or selectively deliver pressure fluid to either lines 46 or 48 depending on the desired direction of operation of the shuttle table. If for example,

the valve 38 delivers pressure fluid to line 46, it is carried through said line and deposited in the bore 50 via the left hand hollow ram 52 (Figure 3). Depositing] of said pressure fluid in said bore will urge the table to Patented Jan. 26, 1 960 52 is securely fixed .to

hand-bores!) via theright hand-hollow ram 52 and 'the. table'will be urged to move to theleft as seen in. Figure 3.- Movementin either direction will be limited by the contact of the respective'operating, segment 30 with the associated abutment 10 secured to the table 2.

As hereinbefore noted, as the table 16 approaches the extreme limit of travel in either direction, it is desirable to reduce its speed so that the contact between the related gland 62 and'the associatedabutment'lt) will be at a slow enough table speed-so-that damage to the structure will not result. valve 38 may be actuated to deliver pressure fluid to line- 46. The fluid will be carried to the left hand ram SZ-and deposited in left'hand bore 50. As the pressure builds up the fluid will act against-the left hand follower 70 causing the springs 68 to compress somewhat whereby free flow will be accommodated into the bore 50. As the pressure fluid fills the bore 50 the fluid will also flow through the orifice 74 and through the peripheral grooves 7 2jof the follower 70 thus filling the entire chamber 50. The pressure of the fluid in the bore 50 will obviously move the shuttle table to the right. It will be noted that as movement to the right is initiated the right hand follower 70 in the'right hand bore 50 is in an intermediate position in said'bore due to the expansion of the related spring 68. As the table '16 moves progressively tothe right the right hand follower 70 approaches the end-of the right end hollow ram 52. At this point in the'stroke the full pressure of the pump is available to move the table at a comparatively rapid rate to the right. As the table movement to the right approaches its extreme limit, the right hand follower 70 engages the end of the right hand ram 52, the surface 71 of the right hand follower 70 engaging the surface 53 of the right hand ram 52.

finish to insure full faced flat engagement therebetween which offers a practical seal to flow of hydraulic fluid therebetween. Additionally, movement of the table to theright forces any hydraulic fluid-which may have been in the right hand bore 50, through the right hand ram SZ and into line 48 and thence to the valve 38 which in turn directs said fluid into line 40' carrying it to the reservoir 34. When the follower 7 abuts the end of the ram 52, free flow of hydraulic fluid past said follower 70 and through the related groove 72 is cut off leaving only the restricting passage 74 free to convey the hydraulic fluid past the follower 70 and into the line 48. With onlythe orifice hole 74 available for passage of hydraulic fluid the movement of the fluid is greatly restricted causing'a pressure build up in the right hand bore 50 behind the right hand follower 70 whereby resistance totable motion to the right is built up. This constrainingaction of the fluid by means of the follower 70 causes areduction in the table speed at its approaches its right extreme position whereby the table is urged to slow down and gradually and easily approach and engage the related abutment 10 thus avoiding any possibility of damage to the press by movement of the shuttle table 16.

The valve 38 may then be energized to direct hydraulic fluid to line 48 and thence to the right hand shuttling device 30. This will initiate movement of the table to the left as seen in Fimlre 3. Inasmuch as the devices '30 on both the right and left hand sides of the shuttle table are identical in construction and operation, the movement to the left and the hydraulic action associated therewith will be identical with that above described.

It will be noted that on a pull back stroke in either direction, as for-example when the table moves to theright from the position indicated inFigure 3, the follower 7t)v may have a tendency to follow theiram 521to an indeterminate position which will vary: frorn stroke to Assuming atypical cycle, the

It should be noted that the surfaces 71 andSShave been machined'and lapped to a very fine 4.. stroke. desirable but may be eliminated by the utilization of the structure illustrated in Figure 4.

Referring now to Figure 4 it is seen that the orifice 74 is enlarged to accommodate a stop member which is received through orifice 74 and preferably threaded into the spring plate 66. The orifice 74 may be made slightly larger than the member 80 to thereby accommodate restricted fluid flow or, if desired, an orifice 74a may be provided to serve this function. I

Stop member-80 is provided with an enlarged end portion 82 which may be adjustably positioned relative to the plate 66 by threading the member 80 a greater or lesser distance into the plate and preferably locked in position by means'of a locknut 81. When the structure of Figure 4 is utilized, the follower 70 always returns to a predetermined position and, as a consequence, the cushioning efliect of the arrangementalways starts at this same point.- In this manner successive strokes of the table-are positively and accurately controlled.

I: claim:

1. In a shuttle table arrangement usable with a press, a horizontally movable table, a frame carrying the table, a table shuttling device mounted in each side of said table and having a portion thereof secured to the frame, eachudevice comprising a bore in the table, a fixed ram disposed within the bore, said ram being hollow and havingtone end-thereof securely attached to the frame, a hydraulic powerline communicating with the ram and through hollow passage therein to the bore, a follower member movably positioned in the. bore, said follower member having peripheral slots therein accommodating flow of hydraulic fluid within the bore between opposite sides ofrsaid follower member, and' a restricting orifice within the follower member establishing communication between opposite sides of the follower member and withv the hollow in said ram.

2'. A table shuttling device according to claiml, and including means to alternately direct pressure fluid to the shuttling devices on opposite sides of the table.

3; In a shuttling arrangement for a press having a table and a bedsupporting the table, a bore in the table, a hollow fixed ram disposed within the bore, a follower member movably disposed in the bore at one side of said ram, peripheral grooves cut in the follower member accommodating flow of pressure fluid in said bore between opposite sides of said member, spring means compressably abutting the follower member and one end of the bore, an orifice formed within the follower member and establishing communications between opposite sides thereof, said follower member being operative to engage the open end of said hollowram at a predetermined position in the movement of said table whereby communication between the hollow ram and the bore is restricted to thatalforded bythe orifice.

4. In a machine of the type described a bed, a table mounted forlimited linear movement'on said bed, means on opposite sides of the table to move said table to its opposite extreme positions, each of said means comprising a hydraulically actuated device having a rammember carried by the bed, a bore in the table partially receiving said ram member, means on-said ram member to convey hydraulic pressure fluid to said how, a follower member freely movable in the bore adjacent the ram member, said follower member having an outer diameter substantially equal to the here, said follower member being operative in'certain' positions of said table to close normal flow of hydraulic fluid between said ram member and said bore, and means on said follower accommodating restrictiveflow of hydraulic fluid between said bore and' saidram member.

5; A' machine offthe type described according to claim 4, wherein said'la'st: mentioned means comprises a restrictingi'orifice-in said'follower member communicating between :said bore-anctsaid; ram member.

In. certaininstances this tendency may be un.-,

6. In an arrangement of the type described,=a bed, a table member on said bed movable to a plurality of extreme positions, abutments on the bed to engage said table member and define said extreme positions, a plurality of operating devices to move said table to said positions, a source of pressure fluid operative to alternately deliver said pressure fluid to said operating devices, each of said devices comprising a fixed ram member carried by the bed, a bore in the table member, passage means in the ram member communicating with the bore, said passage means being operative to convey hydraulic pressure fluid between the source and the bore, and means in the bore operative to restrict communications between the passage andthe bore during certain movements of the table member, said last mentioned means comprising a follower member slidably received within the bore, and apertures in the follower member affording the sole means of communication between the portions of the bore on opposite sides of the follower member.

7. In an arrangement of the type described, a bed member, a movable table member supported thereby, means to move said table member to a determined position, and other means to slow down movement of said table member as it approaches said determined position, said other means comprising a bore in one of said members, a ram secured to the other of said members and telescoped within the bore, a passage in the ram communicating with the bore, and restricting means in the bore operative to seal the passage and restrict flow of fluid between the bore and said passage.

8. In an arrangement of the type described, a bed, a movable table supported thereby, said table being movable linearly to one of two extreme positions, identical operating means on opposite sides of the table operative to move said table to said extreme positions, said operating means being hydraulically operated, a source of pressure fluid, means to alternately direct said pressure fluid to the respective operating means, each of said operating means comprising a bore in the table, a ram secured to the bed and telescoped within said bore, passage means in each ram normally communicating with the related bore, said passage means being operative to convey fluid between the bore and said source, a follower in each bore, each follower being movable therein, a spring compressed between the follower and the related end of the associated bore; the follower in each bore being operative to abut the end of the associated ram and close said passage means when the table is being moved by the other of said operating means, a plurality of grooves peripherally cut on each follower and establishing communication between areas of the bore on opposite sides of said follower, and an orifice formed centrally in said follower and establishing communication between the bore and the passage in said ram when the related follower is abutting and sealing the end of said ram.

9. In a machine of the type described, a bed, a table on said bed movable to a plurality of extreme positions, abutments on the bed to engage said table and define said extreme positions, a plurality of hydraulic operating devices to move said table to said positions, a source of hydraulic fluid operative to alternately direct pressure fluid to said operating devices, each device comprising a bore in the table, a ram fixed to the bed, said ram being telescoped within the bore, a passage in the ram communicating with the bore operative to convey hydraulic pressure fluid between the source and the bore, and means in the bore operative to restrict communication between the passage and the bore during certain movements of the table, said. last mentioned means comprising a follower member movably disposed within the bore, said follower member being operative during said certain movements of the table to abut and seal the end of said passage in the ram, apertures on the follower member ofl ering permanent communication between opposite sides of said member, and an' orifice in the followermember.

arranged to communicate between the'bore and said passage when said follower member has sealed the end of said passage.

10. In an arrangement of the type described, a bed member, a movable table member supported thereby,

means to move said table member to a determined position, and other means to slow down movement of said table member as it approaches said determined position, "said other means comprising a bore in one of said members, a ram secured to the other of said members and telescoped within the bore, a passage in the ram communicating with the bore, and restricting means in the bore operative to seal the passage and restrict flow of fluid between the bore and said passage, said restricting a movable table member supported thereby, means to move said table member to a determined position, and other means to slow down movement of said table member as it approaches said determined position, said other means comprising a bore in one of said members, an element secured to the other of said members, a passage in the element communicating with the bore, and restricting means in the bore operative to seal the passage and restrict flow of fluid between the bore and said passage as said table approaches said extreme position, said restricting means in the bore comprising a follower movable in and solely supported by said bore, said follower having an aperture therein affording communication between the portions of the bore on opposite sides of the follower, and spring means engaging one end of the bore and said follower and urging said follower toward said passage.

12. In a machine of the type described, a movable table having a bore therein, a ram receivable in said bore, fluid passage means in said ram, a cushioning device for said table, said device comprising a follower in said bore, apertures in said follower affording communication between opposite sides of said follower, and an orifice in said follower affording communication between said bore and said passage when said follower is in contact with said ram.

13. In a machine of the type described, a pair of opposed fixed rams, a table having opposed bores therein, said table being slidably carried on said rams, fluid passage means in said rams communicating with their respective bores, cushioning means in each bore comprising a follower slidably received in said bore inwardly of said ram, resilient means urging said follower toward said ram, and openings in said follower affording the sole means of communication between the portions of said bore on opposite sides of said follower.

14. In a machine of the type described, a movable table having a bore therein, a ram receivable in said bore, fluid passage means in said ram, a cushioning device for said table, said device comprising a follower in said bore, apertures in said follower aflording communication between opposite sides of said followenand an orifice in said follower atfording communication between said bore and said passage when said follower is in contact with said ram, and stop means in the bore and engageable with said follower for limiting movement of said follower in one direction.

15. In a machine of the type described, a movable table having a bore therein, a ram receivable in said bore, fluid passage means in said ram, a cushioning device for said table, said device comprising a follower in said bore,

apertures-in saidfollowerafiordiiig communication-be tween opposite sides ofsaid follower, and-"an-oi'ifice in said follower afiording communication between said bore and said passagewhen said follower is in contact with said ram, and stop means in the bore and engageable with said follower for limiting movement of said follower in one direction, said stop means comprising a member slidably received through the follower and receivable in said a'follower slidably received in said bore inwardly of said 15' 2,614,388

ram, resilient meansurging said follower towaxd= said ram, and openings in said followenafiording" the sole means of communication between the portionsof'said bore'on opposite sides ofsaid'follower, and'stop-means for limiting movement of said followertoward said ram,

References Cited in the file of this patent.

UNITED STATES PATENTS 68,994 King Sept. 17, 1867 966,059 Sears Aug. 2, 1910' 1,604,548 Dapron Oct. 26, 1926 1,891,312 Knecht Dec. 20, 1932 2,550,925 Weimar May 1, 1951- Mil1er' Oct. 21, 1952 

